Future continuous tense

Affirmative: I will be driving (I'll be driving)
Negative: I will not be waiting (I won't be waiting)
Questions: Will you be sleeping?
Negative questions: Will you not be working? (Won't you be working?)

1. The future continuous tense is used for activities that will be in progress at a point of time. The action will start before that point of time and will continue after it. The point in time can be given by time expressions or by other activities.

With time expressions:At 8 o'clock I will be travelling to Dorset.
This time tomorrow we'll be lying on the beach.

With some other activity:The shop will be closed. Will you be working?
I'll be sleeping when you come back.

2. It describes the idea that an action will happen in the normal course of events. It refers to routine activities, not intentions, decisions or plans.

Don't worry. I'll be writing to you. (as usual)They'll be leaving on Friday. You can join them. (They normally leave on Fridays.)Everybody will be working on a computer sooner or later. (If nothing special happens.)